Selection Guide for Bioinks for 3D Bioprinting

3D Bioprinting

3D bioprinting is a technology that uses living cells, extracellular matrix, biological factors, and biological materials as raw materials to create precise and controllable 3D cell models and tissue structures. Due to the highly controllable structure and composition, 3D bioprinting is expected to be applied in fields such as cosmetic testing, drug discovery, regenerative medicine, and functional organ replacement.

Three primary categories of 3D bioprinting exist: light-based bioprinting, inkjet/droplet-based bioprinting, and extrusion-based bioprinting, with bioink serving as a crucial component across all these techniques.

Evaluate the Performance of Bioinks

The performance of bioinks can be evaluated in terms of printability, biocompatibility, and mechanical properties.

Printability is used to evaluate the forming performance of bioinks, which requires adjustable and controllable material viscosity, fast phase transition from sol state to gel state, and a wide window of printable process parameters.

Biocompatibility is used to evaluate the ability of bioinks to simulate the extracellular matrix, which requires bioinks to be as close as possible to the microenvironment of the cells in vivo, and cells can proliferate, expand, differentiate, and ultimately communicate with each other within the gelled ink.

Mechanical properties require that the gelled bioink has sufficient strength to support subsequent culture and in vivo implantation processes. Usually, the printed structure needs to be cultured in vitro for a period of time. During the culture process, nutrient perfusion and degradation may occur. Therefore, the printed structure must have sufficient strength to support this process. Similarly, if the strength is too low when implanted in the body, it will lead to implantation failure.

How to Selection Bioinks for 3D Bioprinting

Bioinks can be made from natural or synthetic biomaterials alone, or from a combination of both as hybrid materials. In some cases, cell aggregates without any additional biomaterials can also be used as bioinks for bioprinting. An ideal bioink should have the appropriate mechanical, rheological, and biological properties of the target tissue, which is crucial to ensure the correct function of bioprinted tissues and organs. The most versatile bioinks include gelatin methacryl alcohol (GelMA), collagen, polyethylene glycol (PEG), alginate, and acellular extracellular matrix (ECM) materials. The selection guide for 3D printing bioinks is as follows:

Reference

1. Gungor-Ozkerim P. S.; et al. Bioinks for 3D bioprinting: an overview. Biomaterials Science. 2018, 6(5): 915-946.